gamma rays and ionising radiation

since high doses of gamma rays will kill all living cells, they can be used to treat cancers

the gamma rays have to be directed carefully and at just the right dosage so as to kill the cancer cells without killing too many normal cells

however, a fair bit of damage is inevitably done to normal cells, which makes the patient feel very ill. but if the cancer is successfully killed off in the end, then it's worth it

gamma rays can also be used to diagnose cancer. a radioactive isotope is injected into the patient - a gamma camera is then used to detect where the radioactive isotope travels in the body. this create an image which can then be used to detect where there might be cancer